There is a sweedish poem with words kind of like "Rheea Rheea Runka,
Hesta hit a bunka, Hesta hit a.....   Could you find this poem for me?

I am certain that you're thinking of the old Swedish children's rhyme
"Rida Rida Ranka." The same rhyme is known as "Ride Ride Ranke" in
Norwegian and in Danish. This is often chanted or sung while bouncing
a child on one's knee.

Here is one of many translations of "Rida Rida Ranka" (this is the
Swedish version):

Rida, rida ranka, 
Hästen heter Blanka 
Vart skall vi rida, 
Hem till att fria, 
Hos en Liten piga, 
Vad skall hon heta,
Anna Maja Greta, 
Den tjoka ock feta,
Nar vi kom dit, 
Var det ingen hemma,  
Mei än två små, 
hundar, som, 
Stog under bänken, 
Ock hamla på, 
hänken ock grala 
Woof, woof, woof.

Ride, ride, straight-backed 
The horse is named Blanka 
Where shall we ride 
Home to make a proposal 
To a little maid 
What's her name 
Anna Maja Greta 
The thick and fat 
When we got there 
There was nobody home 
More than two small 
dogs who 
sat under the bench 
And howling 
Woof, woof, woof.

Roots Web
http://www.rootsweb.com/~ialyon/swanson.htm

Another translation may be found here. The melody of the song plays
automatically when you arrive at this page, so you may want to turn
your sound up (or down, if you don't want to hear the music):

Don Erickson's Home Page: Rida, rida ranka
http://home.pcisys.net/~don_erickson/rida.htm

Here are several discussions of 'Rida Rida Ranka' that may be of interest to you:

Newsgroup post, soc.genealogy.nordic
http://groups.google.com/groups?hl=en&lr=lang_en&ie=UTF-8&oe=UTF-8&newwindow=1&safe=off&th=9faed333070ceece&rnum=2

Newsgroup post, soc.genealogy.nordic
http://groups.google.com/groups?selm=%23xR%24r9yH%24GA.303%40cpmsnbbsa02&oe=UTF-8&output=gplain

Newsgroup post, soc.genealogy.nordic
http://groups.google.com/groups?hl=en&lr=lang_en&ie=UTF-8&oe=UTF-8&newwindow=1&safe=off&selm=84l51l%2477c%241%40tron.sci.fi

Newsgroup post, soc.genealogy.nordic
http://groups.google.com/groups?hl=en&lr=lang_en&ie=UTF-8&oe=UTF-8&newwindow=1&safe=off&th=c5e55d207cc1c9e2&rnum=6

Newsgroup post, soc.genealogy.nordic
http://groups.google.com/groups?hl=en&lr=lang_en&ie=UTF-8&oe=UTF-8&newwindow=1&safe=off&th=37ae505df5066fa9&rnum=9

My Google search strategy:

Google Web Search: "rida rida ranka"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22rida+rida+ranka

Google Web Search: "ride ride ranke"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22ride+ride+ranke

I hope this is helpful! If anything is unclear, or if any of the links
do not function, please request clarification; I'll gladly offer
further assistance before you rate my answer.

Best wishes,
pinkfreud

Hi there!
Ready for some reading? 

Things are not always what they seem!

There are actually two versions of this "childrens rime".
One nasty (you have it already)for the commons
One more sublime for the higher standing

Both versions are actually spite against the queen and the king of
Sweden & Norway in early-mid 1300, both considered to be much hated in
their time.
Version 1) as already translated
Consider: Queens name = RANKA av Namour (from Belgium)
          Kings maitresse name = Maja Greta
And what(children)might the two dogs(common 4-letter word those days) represent ?

Version 2)

Rida, rida ranka, 
hästen heter Blanka. 
Liten riddare saa rar 
aennu inga sporrar har. 
Naer han dem har vunnit, 
barndomsro foersvunnit. 

Rida, rida ranka, 
hästen heter Blanka. 
Liten pilt med ögon blaa, 
kungakronor skall du faa. 
När du dem har vunnit, 
ungdomsro försvunnit. 

Rida, rida ranka, 
hästen heter Blanka. 
Andra famntag än av mor 
fröjda dig, när du blir stor. 
När du dem har vunnit, 
mandomsro försvunnit. 

Så sjöng hon för sin älskling 
om livets äventyr 
och log emellan tårar, 
fru Blanka av Namur. 

Och när kung Håkan vunnit 
båd sporrar, land och brud, 
nog mindes han med vemod 
den barndomssångens ljud. 

I want bore you with a long translation but the song is a mild
beautifully hidden critic of the royal succession to come with her son
Håkan Magnusson later king of Sweden and Denmark.

Why was she hated: probably because she was said to be very beautiful
and extremly intelligent (Not a good combination for a women/queen
those days)
Why was her husband (king Magnus Eriksson) hated: ?
That is another complicated story of slander, religion violent death
and powerstrugle.
If you are really intrested I will be happy to fill you in on that and
also the violent and extremly cruel habits of the swedish royalties
those days.
Let me know.

Greetings!

Hi again!
Sorry made an error. Should read King of Sweden and Norway (not Denmark).
Anyway...
Like to mention: Although almost 700 years old this song is still used
in (I dare say) every swedish family (bouncing the child on ones
knee)and at least the beginning of the lyrics is common knowledge.
Want to get an idea how it sounds ? go to
http://mnfolkarts.org/ross/ross.html
Have fun!